This summer, the Y Combinator-backed startup Loblaunched a new developer API which lets companies easily integrate printing and shipping services into their applications. Today, the company is announcing $2.4 million in seed funding from various YC partners and angel investors... With Lob, whose early adopters include CrowdTilt, ZenPayroll, LendUp, LocalOn, and others, developers can automate or print a variety of products on demand, including postcards, photos, flyers, posters, bills, checks, invoices, and more.

The company says it now has over 1,000 paying customers, and just hit $40,000 in revenue at the end of last month. It has also printed a million dollars worth of checks. On the horizon, there’s the potential for Lob to grow even larger, with now two Fortune 500 companies testing the service on a smaller scale. If those trials come to fruition, they could be multi-million dollar deals, the founders tell us.